[Openpvr-devel] Re: ongoing development, ideas, etc

[Robert K. <rku...@ro...>]

"
>    I read your description
>    of your idea of a brute-force versus optimized scheduler.  Good
>    reading.

And the result is very pleasing.  I have been able to include much
more conflicting programming in the new version of the scheduler than
I could in the old version.
"

Is this the version of the scheduler that's on CVS as the .c file?

"
>    For the scheduling algorithm, have you considered the case where
they
>    may be multiple encoders available?

It has occurred to me.  It's not coded for right now but adding it
should not be difficult.
"

That's what I was thinking, until I sat down with a pen and paper and Visio
and started to map out the logic of scheduling.  I think I might be
overcomplicating it a bit.  My idea was to use 1 minute slots for each tuner.
 Earlier, I was think that this would be a huge waste, but then I noticed a
few things:  1)  a two week pull of guide data using XMLTV was only a 4 meg
file.  2)  1440 slots per day per tuner * 14 days of guide data is still not
a huge amount (anymore, since we're talking PCs and even 64MB will give us
some elbow room) I was thinking that each "slot" would simply hold a pointer
to a ProgramID Record in the main XMLTV database.  So when it comes to
scheduling, you have the ability to see how "big" a program is.

What I don't like about the Tivo is it's insistance that if I put in a
1-minute "slop" buffer at the end of a program, it's not going to record the
program that comes after it.

So, Survivor, 1900-2001CST means that "Program X" from 2000 to 2030 is going
to get dropped.  What if I'm willing to lose the 1 minute from the beginning
of Program X?  Too bad.

"
>    3) vbi - there are at least some TVs and VCRs that can obtain guide
>    data encoded in the video signal

Do you mean Guide+?
"

Yes, I was thinking of that as an option.  I'm going to have to see if the
data is plaintext or if it's encoded in some way.  There are a bunch of
Zenith / RCA TV's that tout this feature, but when I googled all I found was
complaints about how it sometimes works, sometimes doesn't.  Seems to be more
dependant on the users cable system and the quality of the signal they're
getting.

"
>    o  Rock-solid A/V sync.  If it can't maintain sync over a long
period
>    of time it's going to be too annoying to use.

Right.  Recent versions of mp1e seem to be good.  I don't usually
watch stuff longer than an hour though so if there is drift beyond
hour long programs, I wouldn't know.
"

If you follow the Tivo and Replay model, then essentially they're always
recording on the off chance that 1)  You want to pause live TV, or 2) You
want to save the buffer

I think that at a minimum we should make sure that there's good sync over a
2hour time period.  That way you can watch movies.

"
>    o  Picking programs through the guide instead of manually.  Manual
>    should still be available though.

Picking for play or recording?
"

I was thinking for recording in this instance "Daily Show" vs "Channel 42,
M-Th, 2200" like you would on a VCR.

I was also thinking about a "hints" file.  For example, the Daily show is on
4 times a day, but only the one that comes on at 2300EST is the "premiere"
one.  The ones that follow in the 24 hour period after that are re-shows. 
I've looked at the XMLTV data for TDS, and there doesn't appear to be any
coding of which episodes are repeats.  Same thing for "Talk Soup", etc.

The Tivo has the same problem with its guide data.  The way I capture it now
is to put in a manual recording for TDS that runs M-F, channel 42, 2200-2230.
 Works great, except TDS doesn't run on Friday, so I need to go in manually
and delete that recording so that I don't get "Comedy Blend".

"
>    o  Sorting saved programs into categories.  Tivo doesn't do this
very
>    well, so everything ends up in one long "What's playing".  I don't
>    have a replay, but I understand that it does this better.

Yeah, I have one long list right now.  One problem is who catagorizes?
What if you don't agree that a program is a drama and think of it more
as a sitcom?  Maybe when you choose to record it, you pick what
catagory it should be filed in?
"

I think that the user should choose, and it doesn't have to be anything to do
with the categories that come in over the wire with XMLTV.  I was thinking
"Bob's Stuff", "Sci Fi", etc.  That way, if I can choose where my programs
are going to show up instead of a long list of items that are all jumbled
together.

"
I have separate boxes for my recording and playing.  I have the PVR
box with TV out and will have the remote, etc. for playback and my
desktop workstation does the recording, just because that's the box
with the most CPU in it.  :-)
"

Are you doing NFS, moving the file over, or something else?

"
>    o  Sharing of programs internally.  If you have a bunch of boxes /
>    tuners as opposed to a super-server, they should be able to share
>    programs that they've saved either through direct streaming or
through
>    file sharing.

Yes.  Replay 4000 like.
"

The Replay 4000's uses straight-up HTTP, sending the file across in chunks. 
What do you think of this as a streaming method?

"
>    o  Adding hard drive space through the LVS.

LVS?  Do you mean LVM?  All my boxes run with LVM.  Using PeeCee
partitions is just arcane.  :-)
"

Yes, thinko on my part.

"
>    Far future:
>    o  Recommendations based on what others watch.  "I see that you
like
>    watching The Simpsons.  88% of viewers that watch The Simpsons also
>    watch "Farscape".  Do you want to add Farscape to your recording
>    queue?

Yeah, that would be neat.  There are privacy issues with that.  You
need to "volunteer" what you watch to a body to coallate the data.  I
am not sure I want someobdy knowing all of my viewing habits.  But I
am a bit of a privacy zealot.
"

Concur.  That's why I said far future.  I didn't say all my ideas were good!

"
>    o  Sharing video over the internet.

Like what Replay (Sonic Blue actually) are being sued over by the
major networks?
"

That's why I put it in the "Don't think it's important" column.

"
I need IR.  Once I get that and have a basic functioning system that
everybody can use, I will look at more useful features.
"

I was looking at IR as well.  Of course, in my visio schematic I have a
decision tree: "Do we need to blast IR?" to take care of external tuners.  I
was looking at the various LIRC projects, and then StreamZap caught my eye
http://www.streamzap.com  - the nice thing about the streamzap is that for
$40, you get a USB IR receiver, and a remote that sure looks an awful like
the Tivo peanut.  No idea is the USB receiver is supported yet, and I didn't
see streamzap listed on the LIRC page for remotes they know about.

"
>    Note:  The information contained in this message may be privileged
<etc>

Is there any way for you to get rid of this disclaimer?
"

Nope - corporate puts it into every email message.  Thanks, MS Exchange!

Switched to rocketmail.


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